Drain the tuna well sqeezing all the water.
Add salt, black pepper, grinded green chili, lime juice and bread crumbs and mix it well.
Mix the diced onion and chat masala in a bowl.
Take some tuna and make a ball and flatten it.
Put the onion filling in middle of the patty and cover it with another ball of tuna
Make sure the patty is nicely binded and a bit flattened like a tikki.
Shalow fry it in a frying pan until it is brown on both sides.
Serve with green chutney or Tartar sauce.
Add more bread crumbs if it falls apart while frying .